Clark A L, Barclay L D, Matyas J R, Herzog W
Human Performance Laboratory, Faculty of Kinesiology, The University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4.
J Biomech. 2003 Apr;36(4):553-68. doi: 10.1016/s0021-9290(02)00424-4.
The mechanical environment is an important factor affecting the maintenance and adaptation of articular cartilage, and thus the function of the joint and the progression of joint degeneration. Recent evidence suggests that cartilage deformation caused by mechanical loading is directly associated with deformation and volume changes of chondrocytes. Furthermore, in vitro experiments have shown that these changes in the mechanical states of chondrocytes correlate with a change in the biosynthetic activity of cartilage cells. The purpose of this study was to apply our knowledge of contact forces within the feline patellofemoral joint to quantify chondrocyte deformation in situ under loads of physiological magnitude. A uniform, static load of physiological magnitude was applied to healthy articular cartilage still fully intact and attached to its native bone. The compressed cartilage was then chemically fixed to enable the evaluation of cartilage strain, chondrocyte deformation and chondrocyte volumetric fraction. Patella and femoral groove articular cartilages differ in thickness, chondrocyte aspect ratio, and chondrocyte volumetric fraction in both magnitude and depth distribution. Furthermore, when subjected to the same compressive loads, changes to all of these parameters differ in magnitude and depth distribution between patellar and femoral groove articular cartilage. This evidence suggests that significant chondrocyte deformation likely occurs during in vivo joint loading, and may influence chondrocyte biosynthetic activity. Furthermore, we hypothesise that the contrasts between patella and femoral groove cartilages may explain, in part, the site-specific progression of osteoarthritis in the patellofemoral joint of the feline anterior cruciate ligament transected knee.
力学环境是影响关节软骨维持与适应的重要因素，进而影响关节功能及关节退变进程。近期证据表明，机械负荷引起的软骨变形与软骨细胞的变形及体积变化直接相关。此外，体外实验表明，软骨细胞力学状态的这些变化与软骨细胞生物合成活性的改变相关。本研究的目的是运用我们对猫髌股关节内接触力的认识，来量化生理大小负荷下原位软骨细胞的变形。将生理大小的均匀静态负荷施加于仍完全完整并附着于其天然骨骼的健康关节软骨。然后对压缩后的软骨进行化学固定，以评估软骨应变、软骨细胞变形和软骨细胞体积分数。髌骨和股骨沟关节软骨在厚度、软骨细胞纵横比以及软骨细胞体积分数的大小和深度分布方面存在差异。此外，当受到相同压缩负荷时，髌骨和股骨沟关节软骨在所有这些参数上的变化在大小和深度分布上也有所不同。这一证据表明，体内关节负荷期间可能会发生显著的软骨细胞变形，并可能影响软骨细胞的生物合成活性。此外，我们假设髌骨和股骨沟软骨之间的差异可能部分解释了猫前交叉韧带切断膝关节髌股关节骨关节炎的部位特异性进展。
